This is a major change to the way block metadata is handled within the PM core. This separates variant metadata (which really ought to be part of the ID) from state metadata, and in a couple of cases flattens separate states of blocks together.
The result of this is that invalid variants can be much more easily detected, and additionally state handling is much cleaner since meta is only needed at the serialize layer instead of throughout the code.
* Fixed an age-old light calculation bug causing solid blocks to filter their own light, fixed#375, probably fixed#288
Light spread reduction should be done based on the _target's_ light filter level, not the source.
* Revert "Fix Glowing Obsidian lighting"
This hack is no longer necessary.
This reverts commit 35c33ba980.
* Fixed wrong light levels for torch and redstone torch
* Take adjacent light levels and opacity changes into account, block light will now spread when an obstruction is removed, close#455
* Added timings for Level->setBlock() and lighting updates
